168

FOUNDRY WORK

The most remarkable fact in connection with machine moulding after
that of the very numerous variations in the designs in use is that of the

IX XV X I KX V XX

Fig. 76.—Portion of Pattern A being drawn through Stripping Plate B lined with White Metal.
C, Pattern plate. D, Frame of Machine.

enormous growth in their dimensions and capacities. Patterns, the castings
from which weigh several tons, are moulded on jar-ramming machines, and

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Fig. 77

Figs. 77 and 78.—Brake Shoe, pattern part moulded
A, Pattern part for bottom. B, That for top box. C, Pattern plates.

those of several hundredweights on hand-operated kinds. Though the
movable parts are heavy, their mass is counter-weighted with weights or
springs, and movements are rendered easy with levers and gears. For power